The invention relates to a Reed-Solomon type error correction device and an optical reading apparatus comprising such a device. The invention applies in particular within the context of error correction in apparatuses for reading optical or magneto-optical disks.
The compact disc, generally abbreviated to `CD`, was introduced onto the market in 1982. Given the need for media of ever larger capacity and in order to take account of developments in the fields of the recording, coding and reading of data, a new standard has recently emerged. This is the so-called DVD standard. The latter relies, for reading, on similar principles to those of CD, but allows a greater density of information.
Compatibility of CD and DVD readers is obviously desirable for users. However, the coding of the data in the two standards is very different: CD and DVD data packets are of different length and use a different kind of interleaving, as well as different parameters for error correction.
Typically, in respect of Reed-Solomon type error correction, in order for a reading apparatus to be able to decode both the CD format and also the DVD format, two circuits, dedicated respectively to CD type error correction and to DVD type error correction would be used within the same apparatus.
It is obvious that this solution is not satisfactory, since redundant elements are employed, thereby raising the cost of the device. Moreover, given the difference in format of the DVD and CD type data packets to be processed, it is difficult to find a configuration which is satisfactory for both cases.
The invention consequently proposes a correction device which can perform the correction of both formats.